The present invention provides a process for preparing esterified chroman compounds from technical grade purity 2,6,6-trimethyl-cyclohex-2-ene-1,4-dione (4-oxo-isophorone, KIP), wherein the esterified intermediate is reacted directly to give the desired chroman compounds without an additional purification step.
The most important compound in this group of substances is vitamin E which is mostly marketed as an ester. Chroman compounds are generally important for use as pharmaceuticals, animal food additives and antioxidants.
The reaction to give vitamin E acetate proceeds as follows: ##STR1##
This shows that 2,3,5-trimethylhydroquinone diesters are valuable intermediates for the production of chroman compounds.